What is a Corona ?

A. Corona is a diffuse discharge from a single sharp conductor that slowly releases some of the available energy. Generally, corona on its own is capable of igniting a gas.
B. Corona is a diffuse discharge from a single sharp conductor that slowly releases some of the available energy. Generally, corona on its own is incapable of igniting a gas.
C. Corona is a diffuse discharge from a single sharp conductor that slowly releases some of the available energy. Generally, corona on its own is incapable of igniting a gas if it is a lean mixture